M4maths Previous Puzzles

06 Oct 2009 what will be the next

Next number in the sequence
15, 161, 1771, 19481, 214291 is

OPtion

1) 1942651
2) 135611101
3) 2424561
4) 1357101
5) 345372101
6) 1357201
7) 23651121
8) 1764924
9) 125461
10) 234255

Solution

First number is 15
Second number is 1 |1 + 5| 1 = 1|6|1=161
Third number is 1 |1 + 6| 6 + 1 | 1 = 1|7|7|1=1771
Fourth number is 1 |1 + 7|7 + 7|7 + 1| 1
= 1| 8 | 14 | 8 | 1
= 1 |8 + 1|4 | 8 | 1 (here 1 is carry)
= 1|9|4|8|1 = 19481
Fifth number is 1 |1 + 9 | 9 + 4| 4 + 8 | 8 + 1 | 1
= 1 | 10 | 13 | 12 | 9 | 1
= 1 + 1 | 0 + 1| 3 + 1 | 2 | 9 | 1
= 2 | 1 | 4 | 2 | 9 | 1 = 214291
Next number is 1 | 2 + 1 | 1 + 4 | 4 + 2 | 2 + 9 | 9 + 1 | 1
= 1 | 3 | 5 | 6 | 11 |10 |1
= 1 | 3 | 5 | 6 + 1 | 1 + 1 | 0 | 1
= 1 | 3 | 5 | 7 | 2 | 0 | 1
= 1357201 (Answer)

Correct Option: 6 Best Solution (1)

Dr.Dipin Singh   15 years AGO

15, 161, 1771, 19481, 214291 is
15... write 1 at each end ....1...1
1+5=6

writ 6 in between 1 and 1 to make 161.
161...... write 1 at each end .....1....1
1+6=7... sum of first and 2nd digit
6+1=7.. sum of 2nd and 3rd digit

so next no is 1771

from 1771

write ....1....1
1+7=8
7+7=14
7+1=8
next no should be
18(14)81
carry from 14 to next 8 will make 19481

From 19481 ......1..1
1+9=10
9+4=13
4+8=12
8+1=9
so next no should be 1 (10)(13)(12)91
Taking carry to next number
1 (10)(14)291....1(11)4291.....214291

From 214291...............1...1
2+1=3, 1+4=5,4+2=6,2+9=11,9+1=10
Next Number should be .. 1356(11)(10)1
Taking carry to next number 1357201


so 1357201... option 6

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